Monodispersivity

This is the basic equation for monodisperse particles in light scattering experiments. We can derive tln-ee relationships by extrapolation. 

Fayet P, Granzer F, Hegenbart G, Moisar E, Pischel B and Woste L 1985 Latent-image generation by deposition of monodisperse silver clusters Phys. Rev. Lett. 55 3002... 

Even when carefully prepared, model colloids are almost never perfectly monodisperse. The spread in particle sizes, or polydispersity, is usually expressed as the relative widtli of tire size distribution,... 

An important step in tire progress of colloid science was tire development of monodisperse polymer latex suspensions in tire 1950s. These are prepared by emulsion polymerization, which is nowadays also carried out industrially on a large scale for many different polymers. Perhaps tire best-studied colloidal model system is tliat of polystyrene (PS) latex [9]. This is prepared with a hydrophilic group (such as sulphate) at tire end of each molecule. In water tliis produces well defined spheres witli a number of end groups at tire surface, which (partly) ionize to... 

One model for rod-like colloids is tire tobacco mosaic vims (TM V), which consists of rods of diameter D about 18 nm and lengtli L of 300 nm [17,18]. These colloids have tire advantage of being quite monodisperse, but are hard to obtain in large amounts. The fd vims gives longer, semi-flexible rods (L = 880 nm, D = 9 nm) [18,19]. Inorganic boehmite rods have also been prepared successfully [20]. 

The fonnation of colloidal crystals requires particles tliat are fairly monodisperse—experimentally, hard sphere crystals are only observed to fonn in samples witli a polydispersity below about 0.08 [69]. Using computer... 

Flard spherocylinders (cylinders witli hemispherical end caps) were studied using computer simulations [118]. In addition to a nematic phase, such particles also display a smectic-A phase, in which tire particles are arranged in liquid-like layers. To observe tliis transition, ratlier monodisperse particles are needed. The smectic-A phase was indeed observed in suspensions of TMV particles [17]. 

Matijevi i E 1976 Preparation and oharaoterization of monodispersed metal hydrous oxide sols Prog. Colloid Polym. Sol. 61 24-35... 

Stdber W, Fink A and Bohn E 1968 Controlled growth of monodisperse silioa spheres in the mioron size range J. Colloid Interface Sol. 26 62-9... 

Pathmamanoharan C and Philipse A P 1998 Preparation and properties of monodisperse magnetic cobalt colloids grafted with polyisobutene J. Colloid Interface Sol. 205 304-53... 

Kose A and Hachisu S 1974 Kirkwood-Alder transition in monodisperse latexes. I. Nonaqueous systems J. Coiioid interface Sc/. 46 460-9... 

Flachisu S and Kobayashi Y 1974 Kirkwood-Alder transition in monodisperse latexes. II. Aqueous latexes of high electrolyte concentration J. Colloid Interface Sol. 46 470-6... 

Kose A and Flachisu S 1976 Ordered structure in weakly flocculated monodisperse latex J. Colloid Interface Sol. 55 487-98... 

In solution, nanocrystals are ideal spectroscopic samples however many of dieir most important properties can only be realized when diey are assembled into more complex stmctures. One way of building complex stmctures is to rely on die inlierent tendency for monodisperse spheres to crystallize. Figure C2.17.3 shows die hexagonal close-... 

Figure C2.17.3. Close-packed array of sub-micrometre silica nanoparticles. Wlren nanoparticles are very monodisperse, they will spontaneously arrange into hexagonal close-packed stmcture. This scanning electron micrograph shows an example of this for very monodisperse silica nanoparticles of -250 nm diameter, prepared in a thin-film fonnat following the teclmiques outlined in [236].

Taleb A, Petit C and Pileni M P 1997 Synthesis of highly monodisperse silver nanopartioles from AOT reverse mioelles a way to 2D and 3D self-organization Chem. Mater. 9 950... 

Sun S and Murray C B 1999 Synthesis of monodisperse cobalt nanocrystais and their assembly into magnetic superlattices J. Appl. Phys. 85 4325... 

Typical pore size distributions for these adsorbents have been given (see Adsorption). Only molecular sieve carbons and crystalline molecular sieves have large pore volumes in pores smaller than 1 nm. Only the crystalline molecular sieves have monodisperse pore diameters because of the regularity of their crystalline stmctures (41). 

Polymerization ofiVIasked Disilenes. A novel approach, namely, the anionic polymerization of masked disilenes, has been used to synthesize a number of poly(dialkylsilanes) as well as the first dialkylamino substituted polysilanes (eq. 13) (111,112). The route is capable of providing monodisperse polymers with relatively high molecular weight M = lO" — 10 ), and holds promise of being a good method for the synthesis of alternating and block copolymers. 

M refer to the density and molecular weight of /, and R is the gas constant. For simplicity, we assume each component to be monodisperse mote complex expressions result when polydispersity is considered (6). This model also assumes the heat of mixing pet unit volume follows a van Laar-type relation where B is... 

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